Messages in this thread | | | Date | Fri, 26 Mar 2010 08:37:24 +0100 | From | Stanislaw Gruszka <> | Subject | Re: [RFC,PATCH 1/2] cputimers/proc: do_task_stat()->task_times() can race with getrusage() |
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On Fri, Mar 26, 2010 at 09:23:44AM +0530, Balbir Singh wrote: > * Oleg Nesterov <oleg@redhat.com> [2010-03-24 21:45:50]: > > > do_task_stat()->task_times() can race with getrusage(), they both can > > try to update task->prev_Xtime at the same time. > > > > Remove this bit of d180c5bc "sched: Introduce task_times() to replace > > task_{u,s}time()". > > One of the reasons for adding this accuracy was to avoid sampling > based noise and errors that occur with utime and stime. > > As long as there is no preemption during the assignment, I think we > should be OK. > > I see two options > > 1. Disable preemption around assignment That one sounds very good.
> 2. Remove task_times() from getrusage() We want more accurate and what more important monotonic values in getrusage.
Stanislaw
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